POPLARS : SORB 223 



by another, dorsal, and open to the anterior. The third 

 scale in is antero-lateral, and only extends partially round 

 the bud (Fig. 17). Then follow the involute leaves and 

 their stipules in spiral succession. 



In some Poplars there are several distichous scales 

 before the spiral begins. 



In P. Canadensis the buds are larger and more angular, 

 pyramidal-pointed and directed outwards ; twigs more 

 angular. It is not easily distinguished from P. nigra, but 

 the buds are larger, more acutely conical-triangular and 

 directed obliquely upwards and outwards, and the greater 

 angularity of the twigs may be accentuated by corky 

 ridges. The branches also are usually more spreading. 



8 8 Terminal buds the larger, fat, 

 ovoid, with blunt points; lateral 

 buds not appressed; a single lower- 

 most bud-scale anterior over the 

 leaf-scar ; twigs rather stout and 

 round, inclined to dark colours 

 e.g. purple-brown, &c. ; pith 

 rounded ; leaf -scars narrow cres- 

 centic with 3 5 leaf -trace bundles. 

 Bud-scales green or olive, or tinged 

 red, shining and viscid. 



Pyrus Sorbus, L. Sorb (Fig. 59 g). Twigs olive-green 

 to pale brown or greyish, glistening above, glabrous, or 

 with traces of hairs towards the tip, fairly stout and 

 round ; bud-scales olive-green with very narrow brown 

 border. Dwarf-shoots stout and much ringed. Buds 

 erect but not appressed, the terminal one larger, leaf- 

 bases slightly prominent ; lenticels numerous and small ; 

 leaf-scars crescentic and with 5 leaf-trace bundles. 



Very few of our trees have viscid buds. JEsculus has 

 been dealt with (p. 150); others are, Alnus, Betula (var. 

 glutinosa), Azalea, Rhododendron. 



